The present invention relates to an object sensing system. The present invention is associated with a method and apparatus for detecting objects behind a vehicle. More specifically, the present invention provides an object detection system that compares information gathered at two different points in time and determines whether to generate a notification about changed conditions behind a vehicle.
Current rearview object detection systems include rearview mirrors and sensor systems. Rearview mirrors typically provide the driver with inadequate rearview information, since they can not convey information on objects located in blind spots alongside the vehicle or show objects beneath the rear of the vehicle. Mirrors are also often ignored by drivers backing up a vehicle. Sensor systems detect objects behind the vehicle and audibly warn the driver. Some systems increase the frequency of audible warnings as the object nears the rear of the vehicle. However, sensor systems typically can not distinguish between different types of objects.
Other sensor systems mount video cameras to the rear and side of a vehicle that feeds images directly to a screen or display that the driver views. The video cameras show three separate screens of information to a driver. The three separate screens may display imagery in addition to the reflections shown by the vehicle""s rearview mirrors. The video imagery, however, can be too much information for the driver to quickly interpret. The imagery can also be distracting, and interfere with the concentration of the vehicle operator.
Each of the currently available techniques for generating notification about the changed conditions behind a vehicle have disadvantages with regard to at least some of the desirable characteristics of systems for presenting information about the condition changes behind a vehicle. It is therefore desirable to provide a system for generating notification about rearward condition changes that exhibit desirable characteristics as well or better than the technologies discussed above.
According to the present invention, methods and apparatus are provided to generate notification about condition changes behind a vehicle. Information about a first set of conditions behind a vehicle is gathered at a first point in time. Information can be gathered using imaging devices, infrared detectors, distance meters, light intensity sensors, and timing devices. At a later point in time, information about a second set of conditions behind the vehicle is gathered. The information gathered at a first point in time is compared to the information gathered at the later point in time to determine differences between the conditions behind the vehicle.
The information gathered can be used to create archetypes. The archetypes can include representations based on edge, line, or texture information from digital imagery. Other archetypes can include information from infrared imagery. The archetypes are compared to determine differences between the archetypes representing separate conditions behind the vehicle. If the differences meet a notification criterion, a notification is generated conveying information about the changed conditions behind the vehicle.
One aspect of the invention provides a computer-implemented method for conveying information about a change in conditions behind a vehicle. The method may be characterized by the following sequence: (1) gathering first information about a first set of conditions behind the vehicle at a first time; (2) gathering second information about a second set of conditions behind the vehicle at a second time later than the first time; (3) comparing the first information and the second information to determine differences between the first set of conditions and the second set of conditions behind the vehicle; (4) determining whether the differences meet a notification criterion; and (5) generating a notification conveying information about a change in conditions behind a vehicle where the differences meet the notification criterion.
The first information can be gathered when the vehicle stops momentarily or is parked. Archetypes for the first and second information are created to allow comparison between first and second information. Quantitative values can be assigned to the differences between archetypes. Archetypes may be generated using edge detection schemes, infrared gradations, texture information, or distance measurements. The quantitative values are multiplied by weighting factors to determine the composite difference between first and second information. The composite difference is compared to a threshold value to determine whether to generate notification about changed conditions behind a vehicle.
Another aspect of the present invention relates to a method for conveying information about changed conditions behind a vehicle. The method may be characterized by the following sequence: (1) gathering first information about first rearward conditions; (2) recognizing that the vehicle is in reverse; (3) gathering second information about second rearward conditions, wherein gathering second information about second rearward conditions occurs after gathering first information about first rearward conditions; (4) creating a first archetype from first information about first rearward conditions; (5) creating a second archetype from second information about second rearward conditions; (6) comparing the first and second archetypes to determine differences between first rearward conditions and second rearward conditions behind the vehicle; and (7) generating a notification conveying information about changed conditions behind a vehicle upon determining that the differences meet a notification criterion.
Comparing the first and second archetypes can include subtracting the first archetype from the second archetype to determine the difference between archetypes. A quantitative value can then be assigned to the difference between archetypes.
Another aspect of the invention is an apparatus for conveying information about changed conditions behind a vehicle. The apparatus can be characterized by the following features: (1) a sensor system for generating data representations of a first set of conditions behind a vehicle at a first time and a second set of conditions behind a vehicle at a second time; (2) a processor coupled to the sensor system, the processor configured to compare the data representations of the first and second set of conditions behind the vehicle to determine differences between the first set of conditions and the second set of conditions; (3) a notification device coupled to the processor, wherein a notification about changed conditions behind a vehicle is conveyed upon determining that the differences meet a notification criterion.
Another aspect of the invention pertains to computer program products including a machine readable medium on which is stored program instructions, tables or lists, and/or data structures for implementing a method as described above. Any of the methods, tables, or data structures of this invention may be represented as program instructions that can be provided on such computer readable media.
A further understanding of the nature and advantages of the present invention may be realized by reference to the remaining portions of the specification and the drawings.